In the malaria transmission cycle, the extrinsic incubation period (EIP) of Plasmodium falciparum in Anopheles mosquito at 25°C is approximately:

• A 9–10 days ✓
• B 16–18 days
• C 24–26 days
• D 30–35 days

Explanation

The extrinsic incubation period (EIP) is the time from ingestion of gametocytes by the mosquito to the development of infective sporozoites in the salivary glands. For P. falciparum at 25–27°C, the EIP is approximately 9–10 days. For P. vivax it is 8–10 days at 25°C. At lower temperatures (below 18°C for P. falciparum), the EIP lengthens or transmission ceases altogether because sporogonic development cannot be completed. The EIP is important in understanding the vectorial capacity and seasonal transmission patterns of malaria.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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